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You searched for subject:(Early Direct Injection). Showing records 1 – 3 of 3 total matches.

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University of Guelph

1. Madan, Pavneesh. Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics.

Degree: PhD, Department of Biomedical Sciences, 2015, University of Guelph

In recent decades infertility in cattle has increased dramatically. Reproductive failure in cattle frequently occurs within the first three weeks following insemination, termed early embryonic mortality, and accounts for 75-80% of all embryonic and fetal deaths. The most common and preferred method for evaluating an embryo’s developmental potential in vitro is by ascertaining the cleavage rate coupled with morphological assessment, in spite of the inherent limitations and inaccuracies of these types of evaluations. A recent endeavor in the industry is to find alternative technologies, such as the study of metabolomics, to identify embryos with the highest chance of developmental success. Advanced analytical techniques such as proton nuclear magnetic resonance (1H NMR) and direct flow injection liquid chromatography tandem mass spectrometry (DFI-LC-MS/MS) allow the culture media of a developing embryo to be analyzed for the presence and depletion of metabolites. From this, the metabolomic fingerprints of embryos differentially growing can be evaluated for the potential presence of biomarkers and bio-patterns. We hypothesize that embryos developing at different rates differ in their metabolomic signature. The objective of this study was to determine the metabolomic signatures of fast (FG) and slow (SG) growing embryos at timed stages of development using 1H NMR and DFI-LC-MS/MS. Aspirated oocytes were matured and fertilized in vitro following standard protocols. Presumptive zygotes were placed individually for culture and media from FG embryos was collected at each developmental stage, 2- cell to blastocyst, along with SG embryos, which were defined as the embryos needing additional 12- to 24 hr to reach equivalent embryo stage. Multivariate analysis of data suggests distinct differences in metabolomic signatures between slow and fast growing embryos. Results of the 1H NMR analysis showed production and consumption of metabolites like pyruvate, lactate, alanine, glutamate, valine, leucine and isoleucine differed between pre and post maternal to embryonic transition phases among SG and FG embryos. Results of the DFI-LC-MS/MS analysis demonstrated production and consumption of metabolites belonging to several classes such as amino acids, biogenic amines, acylcarnitines, sugars, glycerophospholipids, and sphingolipids. Overall, differences among several metabolites between SG and FG bovine preimplantation embryos suggest developmental rate is correlated with a distinct metabolomic signature, and that this may correlate to developmental potential. To our knowledge, this is the first study of its kind to characterize the metabolomic changes in the culture media of in vitro produced SG and FG preimplantation bovine embryos using 1H NMR and DFI-LC-MS/MS techniques. The results provide a positive first step towards the use of metabolomics for the development of a non-invasive tool for assessing embryo viability and the discovery of potential embryo viability biomarkers. Advisors/Committee Members: Madan, Pavneesh (advisor).

Subjects/Keywords: bovine; non-invasive assessment; early embryonic mortality; metabolomics; proton nuclear magnetic resonance; direct flow injection liquid chromatography tandem mass spectrometry

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APA (6th Edition):

Madan, P. (2015). Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics. (Doctoral Dissertation). University of Guelph. Retrieved from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9132

Chicago Manual of Style (16th Edition):

Madan, Pavneesh. “Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics.” 2015. Doctoral Dissertation, University of Guelph. Accessed February 28, 2021. https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9132.

MLA Handbook (7th Edition):

Madan, Pavneesh. “Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics.” 2015. Web. 28 Feb 2021.

Vancouver:

Madan P. Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics. [Internet] [Doctoral dissertation]. University of Guelph; 2015. [cited 2021 Feb 28]. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9132.

Council of Science Editors:

Madan P. Non-Invasive Assessment of In Vitro Derived Bovine Embryos of Different Developmental Rates Using Metabolomics. [Doctoral Dissertation]. University of Guelph; 2015. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9132

2. André, Mathieu. Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection.

Degree: Docteur es, Mécanique et énergétique, 2010, Université d'Orléans

Depuis plusieurs années, l’une des problématiques sociétales est de diminuer les émissions de polluants et de gaz à effet de serre dans l’atmosphère. Le secteur du transport terrestre est directement concerné par ces considérations. Le moteur Diesel semble promis à un bel avenir grâce à son rendement supérieur à celui du moteur à allumage commandé, conduisant à de plus faibles rejets de CO2. Cependant, sa combustion génère des émissions d’oxyde d’azote (NOx) et de particules dans l’atmosphère. Les normes anti-pollution étant de plus en plus sévères et les incitations à diminuer les consommations de carburant de plus en plus fortes, le moteur Diesel est confronté à une problématique NOx/particules/consommation toujours plus difficile à résoudre. Une des voies envisagées consiste à modifier le mode de combustion afin de limiter les émissions polluantes à la source tout en conservant de faibles consommations. La voie la plus prometteuse est la combustion HCCI (Homogeneous Charge Compression Ignition) obtenue par injections directes précoces. Plusieurs limitations critiques doivent cependant être revues et améliorées : le mouillage des parois par le carburant liquide et le contrôle de la combustion à forte charge. Le but de cette thèse est ainsi de mieux comprendre les phénomènes mis en jeu lors de la combustion HCCI à forte charge obtenue par des multi-injections directes précoces. Une méthodologie a été mise au point afin de détecter le mouillage des parois du cylindre, ce qui a permis de comprendre l’effet du phasage et de la pression d’injection sur cette problématique. Une stratégie optimale de multi-injections permettant d’atteindre une charge élevée sans mouiller les parois a ainsi été développée et choisie. Nous avons ensuite pu mettre en évidence le potentiel de la stratification par la dilution en tant que moyen de contrôle de la combustion en admettant le diluant dans un seul des 2 conduits d’admission. Des mesures réalisées en complémentarité sur le même moteur mais en version ‘optique’, ont permis, à partir de la technique de Fluorescence Induite par Laser, de montrer que concentrer le diluant dans les zones réactives où se situe le carburant permet un meilleur contrôle de la combustion, ce qui permet d’amener le taux de dilution a des niveaux faisables technologiquement.

For several years, reduce pollutant and greenhouse gas emissions in the atmosphere is become a leitmotiv. The automotive world is directly affected by these considerations. Diesel engine has a promising future thanks to its efficiency higher than that of S.I. engine, leading to lower CO2 emissions. However, Diesel combustion emits nitrogen oxides (NOx) and particulates in the atmosphere. Emissions regulations are more and more severe, and considerations about fuel consumption are more and more significant. Thus, Diesel engine has to face a NOx/particulates/consumption issue that is more and more difficult to answer. One of the considered ways to reduce pollutant emissions while maintaining low fuel consumptions is to change the…

Advisors/Committee Members: Mounaïm-Rousselle, Christine (thesis director), Bruneaux, Gilles (thesis director).

Subjects/Keywords: HCCI; Injection directe précoce; Mouillage des parois; Multi-injections; Contrôle de la combustion; Homogeneous charge compression ignition; Early direct injection; Wall wetting; Multiple injections; Control of combustion

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

André, M. (2010). Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection. (Doctoral Dissertation). Université d'Orléans. Retrieved from http://www.theses.fr/2010ORLE2051

Chicago Manual of Style (16th Edition):

André, Mathieu. “Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection.” 2010. Doctoral Dissertation, Université d'Orléans. Accessed February 28, 2021. http://www.theses.fr/2010ORLE2051.

MLA Handbook (7th Edition):

André, Mathieu. “Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection.” 2010. Web. 28 Feb 2021.

Vancouver:

André M. Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection. [Internet] [Doctoral dissertation]. Université d'Orléans; 2010. [cited 2021 Feb 28]. Available from: http://www.theses.fr/2010ORLE2051.

Council of Science Editors:

André M. Potentiel de la combustion HCCI et injection précoce : Potential of HCCI combustion and early injection. [Doctoral Dissertation]. Université d'Orléans; 2010. Available from: http://www.theses.fr/2010ORLE2051


Indian Institute of Science

3. Pandey, Sunil Kumar. Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine.

Degree: PhD, Faculty of Engineering, 2017, Indian Institute of Science

Homogeneous Charge Compression Ignition (HCCI) combustion is an alternative combustion mode in which the fuel is homogeneously mixed with air and is auto-ignited by compression. Due to charge homogeneity, this mode is characterized by low equivalence ratios and temperatures giving simultaneously low nitric oxide (NOx) and soot in diesel engines. The conventional problem of NOx-soot trade-off is avoided in this mode due to absence of diffusion combustion. This mode can be employed at part load conditions while maintaining conventional combustion at high load thus minimizing regulatory cycle emissions and reducing cost of after-treatment systems. The present study focuses on achieving this mode in a turbocharged, common rail, direct injection, four-cylinder, heavy duty diesel engine. Specifically, the work involves a combination of three-dimensional CFD simulations and experiments on this engine to assess both traditional and novel strategies related to fuel injection. The first phase of the work involved a quasi-dimensional simulation of the engine to assess potential of achieving HCCI. This was done using a zero-dimensional, single-zone HCCI combustion model with n-heptane skeletal chemistry along with a one-dimensional model of intake and exhaust systems. The feasibility of operation with realistic knock values with high EGR rate of 60% was observed. The second aspect of the work involved three-dimensional CFD simulations of the in-cylinder process with wall film prediction to evaluate injection strategies associated with Early Direct Injection (EDI). The extended Coherent Flame Model-3Zone (ECFM-3Z) was employed for combustion simulation of conventional CI and EDI, and was validated with experimental in-cylinder pressure data from the engine. A new Uniformity Index (UI) parameter was defined to assess charge homogeneity. Results showed significant in-homogeneity and presence of wall film for EDI. Simulations were conducted to assess improvement of charge homogeneity by several strategies; narrow spray cone angle, injection timing, multiple injections, intake air heating, Port Fuel Injection (PFI) as well as combination of PFI and EDI. The maximum UI achieved by EDI was 0.78. The PFI strategy could achieve UI of 0.95; however, up to 50% of fuel remained trapped in the port after valve closure. This indicated that except EDI, none of the above-mentioned strategies could help achieve the benefits of the HCCI mode. The third part of the work involved engine experimentation to assess the EDI strategy. This strategy produced lower soot than that of conventional CI combustion with very short combustion duration, but led to high knock and NOx which is attributed to pool fire burning phenomenon of the wall film, as confirmed by CFD. An Optimized EDI (OptimEDI) strategy was then developed based on results of CFD and Design of Experiments. The Optim EDI consisted of triple injections with split ratio of 41%-45%-14% and advancing the first injection. This strategy gave 20% NOx and soot reduction over the conventional CI… Advisors/Committee Members: Ravikrishna, R V (advisor).

Subjects/Keywords: Homogeneous Charge Compression Ignition Engines (HCCI); Low Temperature Combustion; Multi-Cylinder Heavy-Duty Diesel Engines; Diesel Motor; Diesel Engines; Early Direct Injection; Air-Assisted Injection; Combustion; Diesel Homogeneous Charge Compression Ignition; Diesel Fuels; Diesel-Fueled Engines; Fuel Injection; Internal Combustion Engines; Computational Fluid Dynamics; Mechanical Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Pandey, S. K. (2017). Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2720

Chicago Manual of Style (16th Edition):

Pandey, Sunil Kumar. “Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine.” 2017. Doctoral Dissertation, Indian Institute of Science. Accessed February 28, 2021. http://etd.iisc.ac.in/handle/2005/2720.

MLA Handbook (7th Edition):

Pandey, Sunil Kumar. “Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine.” 2017. Web. 28 Feb 2021.

Vancouver:

Pandey SK. Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2017. [cited 2021 Feb 28]. Available from: http://etd.iisc.ac.in/handle/2005/2720.

Council of Science Editors:

Pandey SK. Exploration And Assessment of HCCI Strategies for a Multi-Cylinder Heavy-Duty Diesel Engine. [Doctoral Dissertation]. Indian Institute of Science; 2017. Available from: http://etd.iisc.ac.in/handle/2005/2720

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